Énumération des fournisseurs

Pour récupérer la liste des fournisseurs qui ont installé leur manifeste ou leurs classes MOF sur l’ordinateur, appelez la fonction TdhEnumerateProviders.

L’exemple suivant montre comment énumérer les fournisseurs.

#include <windows.h>
#include <stdio.h>
#include <tdh.h>

#pragma comment(lib, "tdh.lib")

#define MAX_GUID_SIZE 39

void wmain(void)
{
    DWORD status = ERROR_SUCCESS;
    PROVIDER_ENUMERATION_INFO* penum = NULL;    // Buffer that contains provider information
    PROVIDER_ENUMERATION_INFO* ptemp = NULL;
    DWORD BufferSize = 0;                       // Size of the penum buffer
    HRESULT hr = S_OK;                          // Return value for StringFromGUID2
    WCHAR StringGuid[MAX_GUID_SIZE];
    DWORD RegisteredMOFCount = 0;
    DWORD RegisteredManifestCount = 0;

    // Retrieve the required buffer size.

    status = TdhEnumerateProviders(penum, &BufferSize);

    // Allocate the required buffer and call TdhEnumerateProviders. The list of 
    // providers can change between the time you retrieved the required buffer 
    // size and the time you enumerated the providers, so call TdhEnumerateProviders
    // in a loop until the function does not return ERROR_INSUFFICIENT_BUFFER.

    while (ERROR_INSUFFICIENT_BUFFER == status)
    {
        ptemp = (PROVIDER_ENUMERATION_INFO*)realloc(penum, BufferSize);
        if (NULL == ptemp)
        {
            wprintf(L"Allocation failed (size=%lu).\n", BufferSize);
            goto cleanup;
        }

        penum = ptemp;
        ptemp = NULL;

        status = TdhEnumerateProviders(penum, &BufferSize);
    }

    if (ERROR_SUCCESS != status)
    {
        wprintf(L"TdhEnumerateProviders failed with %lu.\n", status);
    }
    else
    {
        // Loop through the list of providers and print the provider's name, GUID, 
        // and the source of the information (MOF class or instrumentation manifest).

        for (DWORD i = 0; i < penum->NumberOfProviders; i++)
        {
            hr = StringFromGUID2(penum->TraceProviderInfoArray[i].ProviderGuid, StringGuid, ARRAYSIZE(StringGuid));

            if (FAILED(hr))
            {
                wprintf(L"StringFromGUID2 failed with 0x%x\n", hr);
                goto cleanup;
            }

            wprintf(L"Provider name: %s\nProvider GUID: %s\nSource: %s\n\n",
                (LPWSTR)((PBYTE)(penum)+penum->TraceProviderInfoArray[i].ProviderNameOffset),
                StringGuid,
                (penum->TraceProviderInfoArray[i].SchemaSource) ? L"WMI MOF class" : L"XML manifest");

            (penum->TraceProviderInfoArray[i].SchemaSource) ? RegisteredMOFCount++ : RegisteredManifestCount++;
        }

        wprintf(L"\nThere are %d registered providers; %lu are registered via MOF class and\n%lu are registered via a manifest.\n",
            penum->NumberOfProviders,
            RegisteredMOFCount,
            RegisteredManifestCount);
    }

cleanup:

    if (penum)
    {
        free(penum);
        penum = NULL;
    }
}